How to export list of prop values as txt to a certain folder? And how to import them back?
Here's a very simple example, of how you could write out something to a text file:

import os

# Ensure all folders of the path exist
path = "C:/Blender game/YourFolder/"
os.makedirs(path, exist_ok=True)

# Write data out (2 integers)
with open(path + "file.txt", "w") as file:
    file.write("%i %i" % (myprop, myprop2))

# Read back in
with open("C:/Blender game/YourFolder/file.txt") as file:
    data = file.read()
    a, b = map(lambda x: int(x), data.split(" "))
    print("Imported integers:", a, b)


Note that C: is usually the system partition and in order to write to it, you must have elevated rights (run Blender as administrator).

Other possible ways to dump and re-import data is to use the struct module (binary), pickle (python object serialization) or maybe json if you want something human readable. You can come up with your very own text-based format too of course, like shown in my example above, but it can be come tricky to parse very soon. I discourage the use of XML, as it's rather complicated to use in Python without additional libraries.